ImageRotate

Question

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Code¶

ImageRotate.cxx

#include <vtkSmartPointer.h>
#include <vtkImageReader2Factory.h>
#include <vtkImageReader2.h>
#include <vtkImageData.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkInteractorStyleImage.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkImageReslice.h>
#include <vtkImageViewer2.h>
#include <vtkTransform.h>

int main(int argc, char *argv[])
{
  // Verify command line arguments
  if(argc < 2)
  {
    std::cout << "Usage: " << argv[0]
              << " InputFilename" << std::endl;
    return EXIT_FAILURE;
  }

  double angle = 45;
  if (argc > 2)
  {
    angle = atof(argv[2]);
  }

  // Read file
  vtkSmartPointer<vtkImageReader2Factory> readerFactory =
    vtkSmartPointer<vtkImageReader2Factory>::New();
  vtkSmartPointer<vtkImageReader2> reader;
  reader.TakeReference(
    readerFactory->CreateImageReader2(argv[1]));
  reader->SetFileName(argv[1]);
  reader->Update();
  double bounds[6];
  reader->GetOutput()->GetBounds(bounds);

  // Rotate about the center of the image
  vtkSmartPointer<vtkTransform> transform =
    vtkSmartPointer<vtkTransform>::New();

  // Compute the center of the image
  double center[3];
  center[0] = (bounds[1] + bounds[0]) / 2.0;
  center[1] = (bounds[3] + bounds[2]) / 2.0;
  center[2] = (bounds[5] + bounds[4]) / 2.0;

  // Rotate about the center
  transform->Translate(center[0], center[1], center[2]);
  transform->RotateWXYZ(angle, 0, 0, 1);
  transform->Translate(-center[0], -center[1], -center[2]);

  // Reslice does all of the work
  vtkSmartPointer<vtkImageReslice> reslice =
    vtkSmartPointer<vtkImageReslice>::New();
  reslice->SetInputConnection(reader->GetOutputPort());
  reslice->SetResliceTransform(transform);
  reslice->SetInterpolationModeToCubic();
  reslice->SetOutputSpacing(
    reader->GetOutput()->GetSpacing()[0],
    reader->GetOutput()->GetSpacing()[1],
    reader->GetOutput()->GetSpacing()[2]);
  reslice->SetOutputOrigin(
    reader->GetOutput()->GetOrigin()[0],
    reader->GetOutput()->GetOrigin()[1],
    reader->GetOutput()->GetOrigin()[2]);
  reslice->SetOutputExtent(reader->GetOutput()->GetExtent()); // Use a larger extent than the original image's to prevent clipping

  // Visualize
  vtkSmartPointer<vtkImageViewer2> imageViewer =
    vtkSmartPointer<vtkImageViewer2>::New();
  imageViewer->SetInputConnection(reslice->GetOutputPort());
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  imageViewer->SetupInteractor(renderWindowInteractor);
  imageViewer->Render();
  imageViewer->GetRenderer()->ResetCamera();
  imageViewer->Render();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ImageRotate)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkCommonTransforms
  vtkIOImage
  vtkImagingCore
  vtkInteractionImage
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping ImageRotate: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(ImageRotate MACOSX_BUNDLE ImageRotate.cxx )
  target_link_libraries(ImageRotate PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(ImageRotate MACOSX_BUNDLE ImageRotate.cxx )
  target_link_libraries(ImageRotate PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS ImageRotate
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build ImageRotate¶

Click here to download ImageRotate and its CMakeLists.txt file. Once the tarball ImageRotate.tar has been downloaded and extracted,

cd ImageRotate/build

If VTK is installed:

cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./ImageRotate

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.